<template>
    <section class="real-app">
        <input type="text"
         class="add-input"
         autofocus
         placeholder="接下去要做什么"
         @keyup.enter="addTodo"
        >
        <Item :todo="todo"
            v-for="todo in filteredTodos"
            :key="todo.id"
            @del="deleteTodo"
        ></Item>
        <Tabs :filter="filter" :todos="todos" @toggle="toggleFilter" @clearAllCompleted="clearAllCompleted"></Tabs>
    </section>
</template>

<script>
import Item from './item.vue'
import Tabs from './tabs.vue'
let id = 0
export default {
    data(){
        return {
            todos: [],
            filter: 'all'
        }
    },
    components:{
        Item, Tabs
    },
    methods: {
        addTodo(event) {
            this.todos.unshift({
                id: id++,
                content: event.target.value.trim(),
                completed: false
            })
            event.target.value = ''
        },
        deleteTodo(id){
            this.todos.splice(this.todos.findIndex(
                todo => todo.id === id
            ),1)
        },
        toggleFilter(state){
            this.filter = state
        },
        clearAllCompleted(){
            this.todos = this.todos.filter(todo => !todo.completed)
        }
    },
    computed: {
        filteredTodos(){
            if(this.filter === 'all')
                return this.todos
            const completed = this.filter === 'completed'
            return this.todos.filter(todo => completed === todo.completed)
        }
    }
}
</script>
<style lang="stylus" scoped>
.real-app
    width 600px
    margin 0 auto
    box-shadow 0 0 5px #666

.add-input
    position relative
    margin 0
    width 100%
    font-size 24px
    font-family inherit
    font-weight inherit 
    line-height 1.4em
    border none
    outline none 
    color inherit 
    box-sizing border-box
    font-smoothing antialiased
    padding 16px 16px 16px 36px
    border none
    box-shadow inset 0 -2px 1px rgba(0, 0, 0, 0.03)
</style>